Invasives: Bullies of the Plant World


Nonnative Invasive Plant Factsheets

The PRISM is targeting 12 invasive plants that we call the Terrible Twelve. These are the worst invasives in the Blue Ridge, although by no means are they the only worrisome ones.
Click on the name of an invasive to go to a detailed downloadable factsheet.
NOTE: The PRISM does not recommend specific herbicides. Instead we worked with the Virginia Department of Forestry to create an easy-to- use chart that includes their herbicide recommendations for the Terrible Twelve Invasives. Use this chart in conjunction with the invasives factsheets. Click here to download the chart: Virginia Department of Forestry Herbicide Recommendation Chart

Control Methods Factsheets

If you are unfamiliar with a control method mentioned in an invasive plant factsheet, you’ll find it described in detail in one of the three factsheets listed below. The two factsheets on using herbicides are helpful when it comes to understanding how herbicides work and how to use them safely.  Use these three factsheets in conjunction with the invasive plant factsheets.

Factsheet on Invasive Garden Plants

Many of the worst nonnative, invasive plants plaguing our natural and agricultural areas began their careers in home gardens or landscape settings. Some were – and most still are – sold in nurseries and garden centers.  The factsheet linked below discusses the problem of garden plants going wild and lists the most common plants that we recommend you remove from your garden and/or do not plant.

Click here to download Garden Escape Artists


kudzuKudzu smothers trees and shrubs with its relentless growth, forming what are often nicknamed kudzu sculptures. The invasive vine can grow a foot a day during hot summer weather.

More than 90 nonnative plants are listed as invasive by the Virginia Department of Conservation & Recreation – these plants are established in many areas throughout the commonwealth and clearly have the potential to become established in other areas.

Many of these unwelcome invaders, which include vines, trees, grasses, shrubs, and herbaceous plants from other parts of the world, can be seen in profusion throughout the Blue Ridge. Aggressive and fast-growing, these bullies of the plant world steal our natural heritage and ruin our natural resources by overrunning private and public lands. They smother, strangle, and poison the native trees, shrubs, and wildflowers that belong here, and thus destroy wildlife habitat and agricultural land.

In addition, these invasives create eyesores that detract from the visual enjoyment and quality of life that should be inherent to the Blue Ridge. The destruction caused by invasive plants has grown dramatically in recent years, spreading like a metastatic cancer in the environment. Infestations are so extensive that they pose a real threat to Virginia’s economy by damaging the health and beauty of her farms, scenic byways, timber and wild forests, and state and national parks. They cost individuals and the commonwealth hundreds of thousands of dollars spent on control efforts and lost profits, yet because the control measures have been insufficient for the scale of the problem, the destruction continues to escalate. The problem is widespread and growing exponentially.

Rod’s Bittersweet Story

In the fall of 2004, Rod Walker, one of the founders of the PRISM, noticed a vine with eye-catching orange-and-red berries twining up the trunk of a tulip-poplar tree at the edge of the forest on his property in Albemarle County. He noted how attractive the fruits were, but thought little else about the plant. Fast forward to 2014 when a crew from a consulting forestry company began what turned out to be a five-month effort to bulldoze what was now an impenetrable thicket of Oriental bittersweet vines and dead trees on the property. The non-native invasive vines, now consuming more than 15 acres of Rod’s hardwood forest, had caused massive destruction of natural habitat throughout the woodlands, which bordered the Shenandoah National Park.  Some of this land was slated to be timbered and other parts meant to be preserved as wildlife habitat – the invasive vine indiscriminately destroyed them both.

Oriental bittersweet

Oriental bittersweet

Where the vine had come from is anyone’s guess. At first, just a few vines climbed the trees on Rod’s property, but their spread grew exponentially.  Fast-growing and vigorous, Oriental bittersweet, as well as other nonnative invasive vines such as wisteria and porcelainberry, twines around tree trunks, strangling their growth with muscular stems, and sprawls over shrubs, smothering them with a blanket of foliage. As the vines clamber across the treetops, the dense shade they create weakens and kills the native vegetation on the forest floor and suppresses tree regeneration. Oriental bittersweet was killing Rod’s forest, and with no native bio-controls to reign in this invader, the vines continued to grow and spread and wreak havoc with the woods and wildlife.

An ornamental vine widely planted in gardens, Oriental bittersweet is admired for its twining berry-laden vines, which are harvested in fall for Halloween and Thanksgiving decorations. Perhaps the first Oriental bittersweet vine got its start in a North American forest or fencerow when an unknowing person tossed a bittersweet wreath made from garden vines onto the compost heap or over the fence into the bushes where its seeds sprouted the following year. Or perhaps a migrating robin gobbled berries from a garden fence or decorative wreath and “planted” them along its journey south. Likely both these scenarios were repeated many times in many locations throughout the eastern states, and the vine invaded more and more areas as birds carried the seeds in all directions and eventually to Rod’s property.

Oriental bittersweet infestations are serious in Albemarle county and spreading north from there into Greene County and other  counties.  Oriental bittersweet is just one of 12 species that PRISM is targeting.
Rod Mess #1_lr
Today, Rod continues at great cost to battle smaller Oriental bittersweet plants that sprout in the forest in an attempt to prevent them from growing into monstrous tree-killers. Seeds continue to be introduced from neighboring properties where control efforts have not been implemented, so it is an endless battle unless the invasive vine can be controlled on neighboring property. Rod is reaching out as an Area Steward to his neighbors. Check back to this website for a report on the progress in the coming days.